Helpful Terms

Archival Unit (AU): AUs are containers for files preserved in LOCKSS. Each AU has an AUID, associated administrative metadata, and a URLs associated with it. Each LOCKSS server stores AUs in opaque directories on the server filesystem, each AU is self-contained and self-describing. AUs are a meaningful aggregation of content (e.g., a digital collection, a volume of a journal, etc.).

Bag: Bags are based on the concept of “bag it and tag it,” where a digital collection is packed into a directory (the bag) along with a machine-readable manifest file (the tag) that lists the contents. Bags have a sparse structure that envelopes any institutional data architecture and format. It can hold documents, pictures, music, movies and even other folders. Anything digital can be packaged into a bag. Bagging is the act of creating a bag.

Node: An independently-managed, geographically-distributed server running the LOCKSS software that stores digital content and participates in a LOCKSS network with other servers preserving the same content.

Ingest: A term describing the process by which content is transferred or uploaded from a member user to the MDPN’s preservation network.

LOCKSS: Stands for “Lots of Copies Keep Stuff Safe.” LOCKSS is an open-source software program that runs a peer-to-peer network allowing institutions to collect, describe, and preserve access to files. Its main goal is distributed, decentralized digital preservation. Core support for the LOCKSS software is provided by the LOCKSS Program at Stanford University Libraries. Learn more at https://www.lockss.org/. A LOCKSS network is a grouping of LOCKSS servers that are maintained with a common title database. A Private LOCKSS Network (PLN) is any network not directly managed by the LOCKSS Program

Staging Server: A location where AUs created by DART and run through the MDPN’s Pre-Process script are placed to await ingest into the MDPN’s five LOCKSS servers.